Polymer Cancerostatics Containing Cell-Penetrating Peptides: Internalization Efficacy Depends on Peptide Type and Spacer Length.

Eliška Böhmová,Robert Pola,Daniela Machová,Olga Janoušková,Tomáš Etrych,Jozef Parnica,Michal Pechar

doi:10.3390/pharmaceutics12010059

Eliška Böhmová, Robert Pola + Show 5 more

Open Access

https://doi.org/10.3390/pharmaceutics12010059

Copy DOI

Abstract

Cell-penetrating peptides (CPPs) are commonly used substances enhancing the cellular uptake of various cargoes that do not easily cross the cellular membrane. CPPs can be either covalently bound directly to the cargo or they can be attached to a transporting system such as a polymer carrier together with the cargo. In this work, several CPP–polymer conjugates based on copolymers of N-(2-hydroxypropyl)methacrylamide (pHPMA) with HIV-1 Tat peptide (TAT), a minimal sequence of penetratin (PEN), IRS-tag (RYIRS), and PTD4 peptide, and the two short hydrophobic peptides VPMLK and PFVYLI were prepared and characterized. Moreover, the biological efficacy of fluorescently labeled polymer carriers decorated with various CPPs was compared. The experiments revealed that the TAT–polymer conjugate and the PEN–polymer conjugate were internalized about 40 times and 15 times more efficiently than the control polymer, respectively. Incorporation of dodeca(ethylene glycol) spacer improved the cell penetration of both studied polymer–peptide conjugates compared to the corresponding spacer-free polymer conjugates, while the shorter tetra(ethylene glycol) spacer improved only the penetration of the TAT conjugate but it did not improve the penetration of the PEN conjugate. Finally, a significantly improved cytotoxic effect of the polymer conjugate containing anticancer drug pirarubicin and TAT attached via a dodeca(ethylene glycol) was observed when compared with the analogous polymer–pirarubicin conjugate without TAT.

Highlights

Cell-penetrating peptides (CPPs) are short oligopeptides that were designed and described as moieties that are able to readily penetrate into living cells
Reactive polymer precursor 1 was prepared via a controlled radical reversible addition-fragmentation chain-transfer (RAFT) copolymerization providing copolymers with a very narrow distribution of molecular weights even in subsequent reaction steps
The major goal of this study was to investigate the influence of a CPP covalently attached to water-soluble polymer–drug conjugate onto the cellular uptake of the conjugate and its cytotoxicity

Summary

Introduction

Cell-penetrating peptides (CPPs) are short oligopeptides that were designed and described as moieties that are able to readily penetrate into living cells. Most commonly, they are used for delivery of certain cargoes into the cells. The cargo is usually a hydrophobic or a large molecule that does not get across the cell membrane alone. The efficiency of the penetration depends on the particular structure of the CPP, as well as on the cell type, temperature, concentration, and duration of the particular experiment. CPPs may be categorized into the three main groups—positively charged; hydrophobic, and amphiphilic peptides [1]. The detailed structure of each system can substantially affect the cell penetration process

Objectives

Methods

Results

Conclusion